A Guide to AMSB QCD

TL;DR

This paper analyzes the effects of Anomaly Mediated Supersymmetry Breaking on supersymmetric QCD, showing that most theories have stable chiral symmetry breaking minima, with some cases exhibiting incalculable runaways at large field values.

Contribution

It provides a detailed study of AMSB effects on supersymmetric QCD, identifying conditions for stability and incalculability of minima across different flavor regimes.

Findings

Most theories with N_f < 3N_c have stable chiral symmetry breaking minima.

Runaways occur for N_f > 1.43 N_c, indicating incalculable minima at large fields.

The N_f = N_c case remains uncertain due to strong coupling and incalculable Kähler potential terms.

Abstract

We present a careful study of the chiral symmetry breaking minima and the baryonic directions in supersymmetric QCD ($SU(N_c)$ with $N_f$ flavors) perturbed by Anomaly Mediated Supersymmetry Breaking (AMSB). For the s-confining case of $N_f = N_c + 1$ and most of the free-magnetic phase ($N_f \leq 1.43 N_c$) we find that naive tree level baryonic runaways are stabilized by loop effects. Runaways are present, however, for the upper end of the free magnetic phase ($N_f \gtrsim 1.43 N_c$) and into conformal window, signaling the existence of incalculable minima at large field values of ${\cal O} (\Lambda)$. Nevertheless, the chiral symmetry breaking points are locally stable, and are expected to continuously connect to the vacua of QCD for large SUSY breaking. The case of $N_f = N_c$ requires particular care due to the inherently strongly coupled nature of the quantum modified moduli space. Due to the incalculability of critical K\"ahler potential terms, the stability of the chiral symmetry breaking point along baryonic directions cannot be determined for $N_f=N_c$. With the exception of this case, all theories to which AMSB can be applied ($N_f < 3 N_c$) possess stable chiral symmetry breaking minima, and all theories with $N_f \lesssim 1.43 N_c$ (aside from $N_f = N_f$) are protected from runaways to incalculable minima.